This invention relates to a method and a system of preparing an electrocardiogram (EKG) data strip for individual heart lead tracings to be transferred into a permanent record file. The present invention relates particularly to a system in which the tracings can be easily and simply removed from the strip after the tracing has been completed. The detached tracing can then be inserted directly into the record form.
The present invention is a labor saving construction of a widely used medical product, and it provides a considerable saving of time and money by physicians and their technicians, EKG paper is made up in strip form, wound into a roll and used inside an electrocardiogram machine. The machine unrolls the EKG paper as a stylus permanently marks the heart tracing on the paper. The paper itself is a highly specialized paper which has a line grid on one surface, and the paper is, in a majority of cases, heat sensitive so that the stylus actually burns the tracing onto this grid surface of the strip as the strip is pulled through the machine and beneath the stylus at a fixed paper speed of 25mm per second. This speed is determined by the pull of a special roller some distance from the stylus. The timing, speed, meterage, and quality of the EKG paper are all carefully calibrated to insure maximum accuracy. Portions of the tracings recorded on the strip are cut from the strip after recording, and stored in a permanent record holder.
There is a decided need in the field of cardiology for an efficient method of transferring essential, measured parts of the long specialized data strip into the permanent record holder (often a large mounting pad). For example, on taking one individual's EKG, there are 12 separate and distinct wave patterns (labeled leads I, II, III, aVR, aVL, aVF, V.sub.1 -V.sub.6) which are traced on the elongated strip. For subsequent measurement of the various wave lengths and amplitudes it has been found convenient to first transfer typical segments of these wave forms onto a permanent record holder and then to give a complete interpretation in writing on another part of that record holder.
At this point a time consuming task is involved in transferring the 12 leads onto the separate record holder. These 12 separate leads must be cut individually into predetermined pieces so as to fit the record sheet. This cutting currently is being performed by a number of machines -- some simple and others more expensive and complex, but all of which are still rather laborious. In addition to be costly, these machines are all still time consuming since these devices involve a cutting process which is carried out by hand, either with s stamper or by the use of hand tools. Neither cutting process is satisfactory for the physician in private practice or large medical centers, where hundreds of EKG's must be mounted in any given day.
The prior art systems required first marking the tape to locate the individual recordings from the 12 different EKG leads, then cutting out the market individual recordings (either by hand tools or by some cutting device) and finally mounting the separated recordings in the record holder.
Numerous attempts have been made to mechanize this operation, but none of the techniques used prior to the present invention have proved satisfactory.
One example of a mechanical cutting device which has been developed for this purpose is shown in U.S. Pat. No. 3,261,250 to Parks et al. The Parks device is a typical example of a hand stamper.
A major drawback to the Parks device is the fact that it has a single cutting plate which limits its use to single length portions for only one specific mounting card. This is a problem because the typical mounted EKG record card usually contains several ryhthm strips which are longer than the single length portions in order to determine and illustrate the individual's heart rhythm.
Depending on the calibration of the electrocardiogram machine and the brand of data strip used, the cutting device for the Parks et al patent can also present problems in chopping off the upper and lower peaks of tracings. This is a special problem because it is something that is not discovered until recording has been completed, and the strip has been cut.
The Parks device also presents the usual problems of replacing blades when the cutting blades become dull.
Another example of a mechanical cutting device is shown in U.S. Pat. No. 3,817,137 to Thatcher. This device uses a more or less standard paper cutter type of blade in combination with a rather complex viewing and cutting system for the data strip. The Thatcher device requires the data strip to be fed through a track system in the machine. As it is fed through the track, it is scanned and cut with successive up and down manual movements of the cutting blade. All in all it is a rather awkward, laborious system.
A third example of apparatus which has been developed to assist in mounting the tracings in U.S. Pat. No. 3,382,127 to Littmann et al. The Littmann et al device comprises a frame which acts as a press to mount tracings (previously cut from an EKG recording strip) onto an adhesively coated record card.
A further drawback to the prior art existing prior to the present invention was the fact that these devices could accommodate only a standard width EKG paper designated to record a single channel. Several new EKG machines have been introduced which are able to record two and three wave patterns simultaneously, using multiple systems and a considerably wider strip of paper. These newer EKG machines and wider strips of paper entail additional hand cutting steps just to utilize these prior art devices, which is, of course, no solution to the existing handling problem in this art.
There is a definite need to avoid the use of such cutting devices which are burdensome, limited in scope, costly and which quickly become obsolete.
There is also a need for a system which provides easy detachment of portions of varying lengths, which is economical to use, and which is easily adapted to differing and newly developing systems.
It is a primary object of the present invention to perforate specialized EKG paper for the purpose of selecting desired portions, in either single or multiple lengths, in order to facilitate both the detachment of these portions and the transfer onto a permanent record holder.
It is another important object of the present invention to perforate the specialized EKG paper in a particular way so as to allow an efficient transfer of particular portions onto a permanent record holder. The mounting cards in current use have fixed spaces with certain dimensions set aside for attaching EKG strip segments. The present invention permits these dimensions to be perforated into the EKG strip initially so as to eliminate the need for hand cutting later by scissors or other devices.
Another specific object of the present invention is to perforate the EKG paper into predetermined, contiguous, repetitive segments. This allows easy separation of single segments or multiple segments. This also allows physicians or technicians to mark the important segments easily, thereby allowing less skilled personnel to perform the simple task of detaching the segments and transferring them onto the permanent record.
A further object of the present invention is to facilitate performing the EKG tracing itself. The manner in which the EKG data strip is perforated allows the cardiology technician to be able to see at a glance whether the tracing complexes will fit into the segment dimensions. This avoids wrong guesses. It further allows the technician to make adjustments, if necessary, in the course of performing the tracing (e.g., an increase or a decrease in sensitivity), to thereby eliminate unnecessary repeat tracings. It also avoids the problem of chopping off part of the top or bottom of a tracing by a mechanical cutter after the tracing has been completed, and often after the leads have been disconnected from the patient.
There is a tendency, especially prevalent with technicians that are fairly new, to take excessively long tracings. With the present invention most of the recordings are kept quite short because the length of the recording needed can be seen at a glance. That is, a technician can actually see the perforations bounding the segment, and he can discontinue the tracing at the end of the desired segment. This results in a saving of costly paper and can result in substantial savings.
Another object of the present invention is to allow adaptation to any mounting system in use. This adaptation is accomplished while still permitting the EKG data strip to be used in all existing EKG machines with no modification of the machine required. This feature of the present invention thus provides the simplest, most economical approach to the problem of accommodating a wide variety of mounting record cards.
A further object of the present invention is to allow easy adaptation to new and developing systems intended for multiple, simultaneous recordings. The perforated EKG data strip of the present invention can, for example, readily be adapted for use with machines which ran three leads at one time.